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Working Smarter, Not Harder: Pragmatic Approaches to Biofuels

Petroleum fuels are a finite resource. Though there are differing opinions on when exactly these fuels will run out, there is no question that they will eventually be depleted. Thankfully, Dr. Sandun Fernando, an associate professor of biological and agricultural engineering, is on a quest to extend the life of petroleum oils in the most economically and energy efficient ways possible.

Dr. Fernando and his lab are finding unconventional ways to turn biomass, such as trees and algae, into biofuels. These fuels are then compatible and even comparable to petroleum fuels like gasoline.

Turning Biomass into Hydrocarbon Fuels

Hydrocarbon fuels are the world’s primary energy source. One method for producing hydrocarbon fuels is using biomass. However, converting biomass to hydrocarbon is economically challenging because of the presence of significant amounts of oxygen in the biomass that must be removed.

The conventional method of production requires large quantities of hydrogen to remove the oxygen, commonly referred to as deoxygenation. “Gaseous hydrogen (H2) is not a raw material found in nature in significant quantities,” said Dr. Fernando. “It must be commercially produced using steam to reform natural gas, or methane.”

Through funding from a National Science Foundation grant, Dr. Fernando and his team of five graduate students have actually found a way to combine methane directly with the biomass in the presence of a catalyst to produce hydrocarbon fuels, eliminating the need for commercially produced hydrogen.

Although methane is quite stable and difficult to activate, their experiments indicate that glucose, a major building-block of biomass, in the presence of special catalysts assist in the methane C-H bond breakage. The hydrogen resulting from the methane activation appears to create a hydrogen-rich environment that is conducive to the deoxygenation reactions.

“Our technique paves the way for the direct use of natural gas, which is a naturally occurring and abundant raw material, in place of hydrogen to sustainably produce biomass-based hydrocarbon fuels,” Dr. Fernando added. “This efficient method saves producers both energy and money.”

Dr. Fernando’s lab is now working with different temperatures and pressures at which the biomass, natural gas, and catalyst are combined. He believes that increasing the pressure will likely increase the yields of fuel produced.

The innovativeness of Dr. Fernando’s lab doesn’t stop here. His team has also set their sights on another form of biomass – algae.

Solvent Phase Algal Migration (SPAM)

Microalgae has proven to be a promising source of lipids for biofuel production. However, extracting the lipids from algae is difficult because of the extreme amount of water that dilutes the algae.

“About 99.9% of the weight in an algae sample is water,” said Dr. Fernando. “It’s an expensive process to remove that much water. Once the water is removed, the algae must then be mixed in a solvent phase for the algal oil, or lipids, to be harvested.”

Once again, Dr. Fernando and his team have taken the unconventional approach, solvent phase algal migration (SPAM), to extracting algal oil. His lab, with funding support from National Alliance for Advanced Biofuels and Bioproducts (NAABB) and Texas A&M Agrilife Research, has found a special polymer that when added to an algae-water sample attaches to the algae cell surface. The polymer then makes the algae cells hydrophobic so that they repel the water. Once the algae cells become hydrophobic, the polymer then migrates the algae directly into solvent phase.

“It’s really an amazing process,” added Dr. Fernando. “By using this special polymer, we can dewater the algae while migrating the cells into solvent phase to harvest the algal oil. It solves the problem of the high costs associated with using algae as an energy source.”

Effect of surfactant on miscibility of algae with solvent. (a) 0.1 % TSS algae with solvent (b) 0.1 % TSS algae mixed with polymer surfactant and then mixed with solvent (c) 10 % TSS algae with solvent and (d) 10% TSS algae mixed with surfactant and then mixed with solvent.

The video below shows the process of adding the polymer to the algae-water sample and the separation that occurs shortly after.

The old adage of “working smarter, not harder” can pay off, especially when it saves money and energy. Because of their unconventional, pragmatic approaches, Dr. Fernando and his team have truly altered the future of biofuel production.